The Belgium international is training with Chelsea for the first time since joining from Genk for £7million in 2011 after spending the previous three seasons on loan at Atletico Madrid.

Courtois is expected to make his long-awaited debut in the friendly at Werder Bremen on Sunday, meaning his competition with Cech is about to intensify.

Cech wants to remain at Stamford Bridge but with Chelsea needing to sell a foreign player before the window closes to meet the quota in the Champions League and Premier League, he is in a vulnerable position.

Courtois feels he can only benefit from working with Cech at the club and said: “Petr has had a really nice 10 years here. He’s one of the best goalkeepers in the world. You can learn a lot from every keeper you train with.

“Every goalkeeper can have a type of thing they are usually good at so when you see them train you can learn from him and other keepers, too. It helps you during your training.

“I signed with Chelsea three years ago but because of the loan it took until Thursday to have my first training session, so I’m really happy to be here.”

Mourinho has admitted Cech is ready to fight for his place but significantly labelled Courtois as “the best young keeper in the world” and said Mark Schwarzer is “ready to be the second-choice keeper” next term.

Courtois believes the goalkeeping situation is indicative of the strength in depth throughout the squad and sees it as a positive sign for the club’s pursuit of silverware.

He added: “We have a really good team of players, a lot of quality — it will be a real battle to be in the starting XI. That’s good because if you want to win all the trophies in one season you need a big group with a lot of quality.

“If there are only 12-13 you can’t achieve that. We need everybody and hopefully we can win the trophies.

“It’s great there is competition for places. With Belgium we experience the same thing. It helps the players improve and play even better.”

Courtois, 22, has re-joined his parent club full of confidence having been a key member of the Atletico Madrid side that won the La Liga title and reached the Champions League Final last season.

Two of Chelsea’s new summer signings were acquired from Atletico — Diego Costa and Filipe Luis — and Courtois admits their presence will help him settle quicker into his new surroundings.

He told Chelsea TV: “It’s nice when you arrive to know that you’re not alone. I remember my first day at Atletico where I didn’t know anybody and it was a little weird.

“When you have team-mates who have already been here for over a week they can help you. It’s nice to find good friends, they [Costa and Luis] were like that with me at Atletico so it’s good that they’re here.

“I gained a lot of experience playing some important games. In every aspect of being a goalkeeper I improved. As a young keeper you can learn in every training session. I learned a lot.”